Re: Do i really need to use a chain guide?
A too loose chain can be downright dangerous. If it bunches up on the engine drive sprocket, or comes off the rear wheel sprocket it will be the best brake you can imagine. Sudden stop, for sure and can result in damage to the engine case, rear spokes/rim etc. I'm a firm believer in chain tensioners for several reasons. Chains, even good quality industrial chain will wear and loosen over time. If your bike does not have adjustable drop outs then you'll be faced with cutting the chain and using half-links to keep the tension right. Another reason I like them is that they help guide the chain onto the rear sprocket, if installed correctly. The kit tensioners have some design problems in that they often do not run true to the chain angle when installed on the chain stay. They all seem to require a slight twist to get the pully wheel exactly parallel to the chain path. In addition the tensioner bracket needs to be secured to the frame of the bike to prevent it from rotating into the spokes under load. I've used a 10/32 screw through a hole drilled completely through the bracket and chainstay and others have had good luck with a self tapping screw. Currently I have stopped using the kit tensioner bracket and have opted for a welded bracket that I know will not/ can not move. Hope this helps and it might interest you to know that Dan and I usually see eye to eye on everthing else.
Age and Treachery Will Always Triumph
Over Youth and Skill & "Charlie Don't Ride"